/**
 * @projectName: com.xiayuanxing.designPattern
 * @className: Screen
 * @author: xiayuanxing
 * @description: TODO
 * @date: 2021/12/28 16:15
 * @version: 1.0
 */
public class Screen {

    private static Screen instance = new Screen();

    public static Screen getInstance() {
        return instance;
    }


    public void up(){
        System.out.println("Screen up");
    }

    public void down(){
        System.out.println("Screen down");
    }
}
